Fix race condition in subscription TAP test 021_twophase The test did not wait for all the subscriptions to have caught up when dropping the subscription "tab_copy". In a slow environment, it could be possible for the replay of the COMMIT PREPARED transaction "mygid" to not be confirmed yet, causing one prepared transaction to be left around before moving to the next steps of the test.
One failure noticed is a transaction found in pg_prepared_xacts for the cases where copy_data = false and two_phase = true, but there should be none after dropping the subscription. As an extra safety measure, a check is added before dropping the subscription, scanning pg_prepared_xacts to make sure that no prepared transactions are left once both subscriptions have caught up. Issue introduced by a8fd13cab0ba, fixing a problem similar to eaf5321c3524. Per buildfarm member kestrel. Author: Vignesh C <vignes...@gmail.com> Reviewed-by: Amit Kapila <amit.kapil...@gmail.com> Discussion: https://postgr.es/m/caldanm329qaz+bwu--bw6gjbnsz8-38cde8qwofafub7nv6...@mail.gmail.com Backpatch-through: 15 Branch ------ REL_17_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/6ea812f4dc634af01feb06fc3da45d53f5a1ec83 Modified Files -------------- src/test/subscription/t/021_twophase.pl | 7 +++++++ 1 file changed, 7 insertions(+)